1. Technical Field
The present invention relates to flat metallic gaskets, such as, for example, cylinder head gaskets on internal combustion engines.
2. Related Art
After the use of multilayer flat metallic gaskets as a replacement for cardboard and fabric-based gaskets became known in the art, the widest range of embodiments have become known.
As the present state of the art, explicit reference is made to the document WO 03010450, which discloses a two-layer or multi-layer flat metallic gasket, which has an inlaid compression limiter in the region of the combustion chamber. In WO 03010450, the compression limiter lies in the plane of the mid-layer of the flat metallic gasket. The compression limiter is fixed in the flat metallic gasket by means of hollow rivets, wherein one annular segment of the each of the hollow rivets surrounds the compression limiter and another annular segment of each of the hollow rivets surrounds the mid-layer of the flat gasket. The principle is most clearly seen for example in the mounting of “floating” brake discs, such as are known in motor cycles. Another way of fixing compression limiters to flat metallic gaskets is known from for example American patent U.S. Pat. No. 6,027,124. This document discloses a means of fixing compression limiters to a flat metallic gasket based on lugs. In this method, lugs which are formed from the compression limiter are pushed through slots in the flat metallic gasket, so that the compression limiter is fixed to the flat metallic gasket with a positive fitting.
Also known is the fixing of compression limiters, stopper coatings or stopper layers by means of welding methods, such as, for example laser-welding, to other sealing layers.
Stopper layers in this context are used, especially in cylinder head gaskets, to increase the compressive pressure in the region around the combustion chamber, to allow the combustion chamber to be reliably sealed off. Cylinder head gaskets often have other sealing regions as well, in order to seal, for example, coolant-water lines or oil lines, which are passed from the engine block to the cylinder head through the cylinder head gasket.